I also must point out the manuals! Besides being nicely designed, the Gizmo manual has a reference picture for every step of the build.
I worked in some additional detailing with a few extra things: brad fasteners, plastic finger nail beads, some rust powder and reflective tape.
I put the daughterboard together first. Before assembly, I sanded the 3D-printed board and applied semi-gloss clear coat to bring down the shine.
By pure luck, I found brad fasteners the same size as the printed gold fingers. I clipped the legs off and superglued them to the board.
*From the time spent on these, I now want to learn how to do electroplating. I’m a bit accident-prone and would need some cyanide. What could go wrong?
After I punched out the circuit board holes, I glued down silver fingernail beads (and a few gold ones) to add more depth to the solder points. The beads are flat on the bottom and ridiculously tiny. I switched to angled tweezers instead of the ones pictured.
I didn’t put beads down anywhere that would interfere with the components—after I did a few by accident and had to scrape them off.
In addition to what was printed on the board, I added more beads to make the overall texture denser. I roughly based positioning off of reference photos of the real calculator. I used rust powder to add slight weathering, especially on the gold beads. Then I hit the whole thing with clear coat to bring down the shine and help seal in the added pieces.
I started attaching the resistors, capacitors, and diodes. The wiring runs through the holes and is secured with superglue on the back. I tried to keep everything neat, however, the real Sanyo boards are a mess.
Fourteen of the resistors have to be attached in a standing position. The legs need to be bent and kinked. I added the bend by wrapping the legs over a small screw driver. The kinks were a battle of tweezers, and the roughed up wires show it. Luckily, the legs will be covered with heat shrink.
Each bend was unbended for the shrink wrap. The tubing needs to cool completely before re-bending or it will slip away from the resistor bottom.
I was able to get the resistors lined up fairly well, but there’s too much hot glue on the back. I sanded this down and cleaned it up later.
The four LM600X chips are impossible to source now, so Dave built these cool replicas. The small legs need to be inserted manually. After kinking those capacitors, this was smooth and relaxing.
Attaching the nixie tube shelf went mostly well, except for one hitch. I tried to smooth out a small air bubble on the tinted transparency inside the error box, but messed it up. Making a replacement was easy, but taking apart the box was nerve-wracking. My replacement hides the E when powered off, but I can live with it.
I also added small strips of reflective tape to enhance the lighting effects. The LEDs are already bright enough that the increase is only minimal.
I also added big fat shrink wrap over the real circuit board before tucking it away.
I’m embarrassed to show this, but it’s a good example of why you shouldn’t solder in the middle of the night when you have insomnia.
But it’s okay, the heat shrink will cover it…
Look at that wrinkled heat shrink, and I forgot that some of the shrink is clear!
After re-soldering more than half of these, I re-applied heat shrink and moved on to the disc capacitors and black T4125 chips. To keep the chips lined up, I was able to wedge a ruler in place.
To finish the Gizmo, I needed to attach the replica E172C capacitor and connect the daughterboard. I accidentally messed up two of the printed numbers on the capacitor. Luckily, I always have spare dry rub transfers on hand so I replaced the 1 and 7.
The 7 is a little off, but with these numbers being 2 mm big, it is very hard to tell, unless you blow it up in a picture like this. After getting the numbers on, I applied a few clear coats for protection and blending.
I experimented with making the shaver cable removable but it didn’t work out. I used wire and epoxy to make a small extension that I then tapped for a small socket head cap screw.
I made a small hole that’s concealed behind the capacitor. This did keep the shaver cable in place, except it wasn’t tight enough to prevent the cable from pivoting. I went ahead and made the connection permanent with epoxy. With that screw in there, that cable is not coming off.
On the back, I sanded the superglue down and added closed cell foam to create a level surface, which helps the board rest nicely if it’s out of the holster. I left space for the Velcro and made a small route for the battery wiring. I then covered with electrical tape . This will never be visible but I still wanted it to look neater by hiding the superglue.
The completed Gizmo needs to be holstered and attached to the uniform pistol belt. Although it fits nicely behind the belt, I hid the battery holder inside the front of the holster, using a small amount of epoxy. I honestly didn’t think this would stay attached, but it worked on the first try. It’s a very tight fit and two of the black resistors get bent if the Gizmo isn’t lined up carefully when holstering.
Once powered, the Gizmo is controlled with this console on the top of the nixie tube shelf. The black button changes the led pattern and red changes the color.
The Gizmo 8400 Resistor:
Demo of LED functionality (with context):